The visual man-machine interface is constantly trying to improve the images for a wide range of applications: military, biomedical research, medical imaging, genetic manipulation, airport security, entertainment, videogames, computing, and other display systems.
Three-dimensional (3D) information is the key for achieving success in critical missions requiring realistic three-dimensional images, which provide reliable information to the user.
Stereoscopic vision systems are based on the human eye's ability to see the same object from two different perspectives (left and right). The brain merges both images, resulting in a depth and volume perception, which is then translated by the brain into distance, surface and volumes.
In the state-of-the-art, several attempts have been made in order to achieve 3D images, e.g., the following technologies have been used:
Red-blue polarization
Vertical-horizontal polarization
Multiplexed images glasses.
3D virtual reality systems
Volumetric displays
Auto-stereoscopic displays
All of the aforementioned technologies have presentation incompatibilities, collateral effects and a lack of compatibility with the current existing technology.
For example, red-blue polarization systems require, in order to be watched, a special projector and a large-size white screen; after a few minutes, collateral effects start appearing, such as headache, dizziness, and other symptoms associated to images displayed using a three-dimensional effect. This technology was used for a long time in cinema display systems but, due to the problems mentioned before, the system was eventually withdrawn from the market. Collateral symptoms are caused by the considerable difference in the content received by the left eye and the right eye (one eye receives blue-polarized information and the other receives red-polarized information), causing an excessive stress on the optical nerve and the brain. In addition, two images are displayed simultaneously. In order to be watched, this technology requires an external screen and the use of polarized color glasses. If the user is not wearing red-blue glasses, the three-dimensional effect cannot be watched, but instead only double blurry images are watched.
The horizontal-vertical polarization system merges two images taken by a stereoscopic camera with two lenses; the left and right images have a horizontal and vertical polarization, respectively. These systems are used in some new cinema theaters, such as Disney® and IMAX®3D theaters. This technology requires very expensive production systems and is restricted to a dedicated and selected audience, thus reducing the market and field of action. A special interest in the three-dimensional (3D) format has grown during the past three years; such is the case of Tom Hanks' productions and Titanic, which have been produced with 3D content by IMAX3D technology. However, this technology also results in collateral effects for the user after a few minutes of display, requires an external screen and uses polarized glasses; if the user is not wearing these glasses, only blurred images can be watched.
Systems using multiplexed-image shutting glasses technology toggle left and right images by blocking one of these images, so it cannot get to the corresponding eye for a short time. This blocking is synchronized with the image's display (in a monitor or TV set). If the user is not wearing the glasses, only blurred images are seen, and collateral effects become apparent after a few minutes. This technology is currently provided by (among others), BARCO SYSTEMS for Mercedes Benz®, Ford® and Boeing® companies, by providing a kind of “room” to create 3D images by multiplexing (shutter glasses) in order to produce their prototypes before they are assembled in the production line.
3D virtual reality systems (VR3D) are computer-based systems that create computer scenes that can interact with the user by means of position interfaces, such as data gloves and position detectors. The images are computer generated and use vector, polygons, and monocular depth reproduction based images in order to simulate depth and volume as calculated by software, but images are presented using a helmet as a displaying device, placed in front of the eyes; the user is immersed in a computer generated scene existing only in the computer and not in the real world. The name of this computer-generated scene is “Virtual Reality”. This system requires very expensive computers, such as SGI Oxygen® o SGI Onyx Computers®, which are out of reach of the common user. Serious games and simulations are created with this technology, which generates left-right sequences through the same VGA or video channel, the software includes specific instructions for toggling video images at on-screen display time at a 60 Hz frequency. The videogame software or program interacts directly with the graphics card.
There is a technology called I-O SYSTEMS, which displays multiplexed images in binocular screens by means of a left-right multiplexion system and toggling the images at an 80 to 100 Hz frequency, but even then the flicker is perceived.
Only a few manufacturers, such as Perspectra Systems®, create volumetric display systems. They use the human eye capability to retain an image for a few milliseconds and the rotation of a display at a very high speed; then, according to the viewing angle, the device shows the corresponding image turning the pixels' color on and off, due to the display's high speed rotation the eye can receive a “floating image”. These systems are very expensive (the “sphere” costs approximately 50,000 USD) and require specific and adequate software and hardware. This technology is currently used in military applications.
Auto-stereoscopic displays are monitors with semi-cylindrical lines running from top to bottom and are applied only to front and back images; this is not a real third dimension, but only a simulation in two perspective planes. Philips® is currently working in this three-dimension technology as well as SEGA® in order to obtain a technological advantage. Results are very poor and there is a resolution loss of 50%. This technology is not compatible with the present technological infrastructure and requires total replacement of the user's monitor. Applications not specifically created for this technology are displayed blurred, making them totally incompatible with the inconveniencies of the current infrastructure. In order to watch a 3D image, the viewer needs to be placed at an approximate distance of 16′ (40.64 cm), which varies according to the monitor's size, and the viewer must look at the center of the screen perpendicularly and fix his/her sight in a focal point beyond the real screen. With just a little deviation of the sight or a change in the angle of vision, the three-dimensional effect is lost.
In the state-of-the-art, there are several patents, which are involved in the development of this technology, namely:
U.S. Pat. No. 6,593,929, issued on Jul. 15, 2003 and U.S. Pat. No. 6,556,197, issued on Apr. 29, 2003, granted to Timothy Van Hook, et al., refer to a low cost video game system which can model a three-dimensional world and project it on a two-dimensional screen. The images are based on interchangeable viewpoints in real-time by the user, by means of game controllers.
U.S. Pat. No. 6,591,019, issued on Jul. 8, 2003, granted to Claude Comair et al., uses the compression and decompression technique for the transformation of a matrix into 3D graphical systems generated by a computer. This technique consists in converting real numbers matrixes into integer matrixes during the zeroes search within the matrix. The compressed matrixes occupy a much smaller space in memory and 3D animations can be decompressed in real-time in an efficient manner.
U.S. Pat. No. 6,542,971, issued on Apr. 1, 2003, granted to David Reed, provides a memory access system and a method which uses, instead of an auxiliary memory, a system with a memory space attached to a memory which writes and reads once the data input from one or more peripheral devices.
U.S. Pat. No. 6,492,987, issued on Dec. 10, 2002, granted to Stephen Morein, describes a method and device for processing the elements of the objects not represented. It starts by comparing the geometrical properties of at least one element of one object with representative geometric properties by a pixels group. During the representation of the elements of the object, a new representative geometric property is determined and is updated with a new value.
U.S. Pat. No. 6,456,290, issued on Sep. 24, 2002, granted to Vimal Parikh et al., provides a graphical system interface for the application of a use and learning program. The characteristic includes the unique representation of a vertex which allows the graphic line to retain the vertex status information, projection matrix and immersion buffer frame commands are set.
Any videogame is a software program written in some computer language. Its objective is to simulate a non-existent world and take a player or user into this world. Most videogames are focused in enhancing the visual and manual dexterity, pattern analysis and decision taking, in a competitive and improvement (difficulty level) environment, and are presented in large scenarios with a high artistic content. As a game engine, most videogames are divided into the following structure: videogame, game library with graphics and audio engines associated, the graphical engine contains the 2D source code and the 3D source code, and the audio engine contains the effects and music code. Every block of the game engine mentioned is executed in a cyclic way called a game loop, and each one of these engines and libraries is in charge of different operations, by example:
Graphics engine: displays images in general
2D source code: static images, “backs” and “sprites” appearing in a videogame screen.
3D source code: dynamic, real-time vector handled images, processed as independent entities and with xyz coordinates within the computer-generated world.
Audio engine: sound playback
Effects code: when special events happen, such as explosions, crashes, jumps, etc.
Music code: background music usually played according to the videogame's ambience.
The execution of all these blocks in a cyclic way allows the validation of current positions, conditions and game metrics. As a result of this information the elements integrating the videogame are affected.
The difference between game programs created for game consoles and computers is that originally, the IBM PC was not created for playing in it. Ironically, many of the best games run under an IBM PC-compatible technology. If we compare the PCs of the past with the videogames and processing capabilities of the present, we could say that PCs were completely archaic, and it was only by means of a low-level handling (assembly language) that the first games were created, making direct use of the computer's graphics card and speaker. However, the situation has changed. The processing power and graphics capabilities of present CPUs, as well as the creation of cards specially designed for graphics processes acceleration (GPUs) have evolved to such a degree that they surpass by far the characteristics of the so-called supercomputers in the 1980s.
In 1996, a graphics acceleration system known as “hardware acceleration” was introduced which included graphics processors capable of making mathematical and matrix operations at a high speed. This reduced the main CPU's load by means of card-specific communications and a programming language, located in a layer called a “Hardware Abstraction Layer” (HAL). This layer allows the information handling of data associated to real-time xyz coordinates, by means of coordinate matrixes and matrix mathematical operations, such as addition, scalar multiplication and floating point matrix comparison.